Looking for a voltage converter

[ECSI]

Does anyone know where I can get a get a converter to take a typical PLC analog output signal of 4-20mA or 0-10V and convert it to a voltage range of 6-18 VDC for the control of a hydraulic proportional valve? I can find various converters (Weidmuller, Acromag, Action, etc) that convert analog signals, but none seem to be able to give me an output up to at least 18V. The valve itself requires 12V for center position, 6-12V for flow in one direction, and 12-18V for flow in the opposite direction. Thanks

[entertron]

Are you actually looking to drive the valve or just control the position of the valve? What controller are you currently using and what are the I/O requirements? The reason I ask is that it might be possible to configure one of our controllers for that analog output range.

[ECSI]

I am trying to control the position of the valve. It requires 18V for full flow in one direction, and 6V for full flow in the other direction. 12V will put the valve in center position (no flow). I am using an Omron CJ1M PLC with CJ1W-MAD42 Analog unit. Thanks

[Guest budw]

You might try Absolute Process Instruments, Inc., they make a lot of different converters, current loop to DC voltage & DC voltage level to another DC voltage level. See link below http://www.api-usa.com

[Wordman]

You could make a DC amplifier with a voltage gain of 2. Maybe use a op-amp non-inverting amplifier with an emitter-follower buffering the output.

[entertron]

Just to let you know, in checking with my engineer, we would be able to do a 0-18 volt analog output span. Unfortunately, this doesn't help you if you are using Omron for your control.

[ECSI]

hey budw...thanks for the lead! it looks like the V 604 Programmable Universal Transmitter from API will do the trick. Here's the link to it if anyone is interested: V604 Programmable Universal Transmitter Wordman...making my own amplifier was an option, but I figured there gotta be an off the shelf unit somewhere. entertron....I checked out your website. you have some interesting products there. I'll keep you in mind for future projects. Sorry it was too late for this one. Thanks all

[Charles_T46]

Hey ECSI, just wondering how well did you project turn out?

[drforsythe]

[TConnolly]

Many hydraulic proportional valves need a high frequency dither on the valve driver current. I strongly suggest you check with the valve manufacturer's offerings. Most have amplifiers for their valves.